Ionic valve with resistance igniter



Dec. 26, 1950 UHLMANN 2,535,467

IONIC VALVE WITH RESISTANCE IGNITER Filed Dec. 24, 1948 Fig.7

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Patented Dec. 26, 1950 IONIC VALVE WITH RESISTANCE IGNITER Erich Uhlmann, Ludvika, Sweden, assignor to Alimanna Svenska Elektriska Aime ooiaget,

Vasteras, Sweden, a Swedish corporation Application December 24, 1-948, Serial No. 67,233 In Sweden December 31, 1947 7 '5 Claims. 1 In ionic valves havinga, liquid cathode and a resistance igniter permanently immersedtherein, it is generally desirable that the current wave admitted through the igniter for causing the ignition is of a steeply rising character for enabllng the instant of' ignition to be accurately adjusted. As far as hitherto known, however, such a steeply rising voltage wave causes a progressively uncertain function of the igniter, the

ignition being delayed or even failing in more and more cases during the continued operation of the ionic valve.

It has been proposed to improve generally the function of a resistance igniter by normally keeping it at a higher temperature than the rest of the valve apparatus, and such a higher temperature also acts to improve the precision of the instant of ignition. However, the means for raising the temperature of the igniter as hitherto known have not made the operation satisfactory. They have either consisted of a separate heating element, for instance a resistance wire surrounding the igniter, or of means for passing an alternating current through the igniter and the liquid cathode. A separate heating element cannot efiect the uniform heating to a high temperature necessary for really improving the ignition, and an alternating current passing through the ignitzr and cathode will cause, during the intervals when it flows in the direction from the cathode to the igniter, a collection of small particles around the igniter which will disturb its regular function. Also, the means for normally forcing an alternating current through the igniter have hitherto consisted of a source of current connected in series with that giving the ignition impulses, and the result of this has been a too large consumption of energy for the heating current. According to a preferred form of the present invention, therefore, the current source for heating the igniter is connected in parallel with the source of the ignition impulses, which it is possible to accomplish in a simple manner when the former is a direct current source, as the way of the ignition impulses therethrough can be blocked by an unidirectional electric valve (half-wave rectifier). Preferably, the heating current is caused to flow through the igniter only during such portions of the alternatin current cycle, when an ignition is not intended.

Three forms of igniter circuits according to the present invention are diagrammatically illustrated in Figs. 1-3 of the accompanying drawing.

In all the figures, I designates the evacuated ionic valve vessel, Zits cathode, and a resistance igniter permanently immersed in said cathode, and ii the anode. In rug. 1, the igniter is fed through a, small valve 4, provided with a control grid, from the same source or current as the main valve. The small valve 4 may be an electronic (high-evacuated) one or an ionic (gasiilleu) valve. According to the 101111 or the present invention shown in this figure, the secondary winding or a transrormer a is connected in series with a unidirectional current valve 6 between the resistance igniter and the cathode of the main valve. The primary winding of the transl'ormer 5 is connected to the alternating current circuit feeding the main valve l in such a manner, that a current traverses the secondary wind.-

ing in the direction permitted by the valve 6 only during the semicycles when the igniter receives no impulse from the valve 4. In this manner, the igniter is kept at an appropriate temperature, even if the igniting impulses are too short to heat it materially, and at the same time, disturbing particles in the cathode liquid are kept away from the igniter by the action of the unidirectional current flowing therethrough.

Fig. 2 differs from Fig. 1 first in that the ignition impulses to the igniter 3 come from a condenser which is discharged through the valve 4 when the latter is released, the charging device of this condenser being not shown, as it may be of any known type. Secondly, Fig. 2 differs from Fig. 1 in that the transformer is provided with an adjustable primary tap whereby the heating can be adjusted according to the conditions. These two modifications are of course independent of one another. A valve 6 for the heating current is arranged as in Fig. 1.

In Fig. 3, the ignitien impulses to the igniter 3 are sent from a condenser I through a saturable reactor 3, for instance a direct current saturable reactor for enabling the phase of said impulses to be easily adjusted. A parallel circuit comprising a valve 9 and an ohmic resistor it is provided in an usual manner. The heating transformer 5 is here connected in series with a direct current saturable reactor ll on its primary side, so that the heating can be autimatically adjusted by the 3 connected in the same manner in Fig. 3 as in the other figures.

I claim as my invention: 1. An ionic valve comprising an evacuated vessel having a liquid cathode and at least one main 5 .rent source to said igniter for imparting ignition voltage impulses thereto, and additional means for connecting a current source to said igniter and cathode, said last means furnishing a unidirectional current from said igniter to said cathode and said last means permitting th flow of current therein during non-arcing intervals only of the valve.

3. An ionic valve comprising an evacuated vessel having a liquid cathode and at least one main anode therein, a resistance igniter permanently immersed in said cathode, at least one current source, means for periodically connecting a current source to said igniter for imparting ignition voltage impulses thereto, and additional means connected in parallel to said first means for connecting a current source to said igniter and cathode, said last means furnishing a unidirectional current from said igniter to said cathode.

4. An ionic valve comprising an evacuated vessel having a liquid cathode and at least one main anode therein, a resistanc igniter permanently immersed in said cathode, at least one current source, means for periodically connecting 3, current source to said igniter for imparting ignition voltage impulses thereto, additional means for connecting a current source to said igniter and cathode, said last means furnishing a unidirectional current from said igniter to said cathode, and means responsive to variations in an operational quantity of the valve to control said last means.

5. An ionic valve. comprising an evacuated vessel, a liquid cathode and at least one main anode therein, a resistance igniter permanently immersed in said cathode, means for imparting ignition voltage impulses to said resistance igniter, and a circuit embracing said igniter and cathode, a transformer winding, and a unidirectional valve element admitting current through said circuit only in the direction from said igniter to said cathode.

ERICH UHLMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,231,587 Miles Feb. 11, 1941 FOREIGN PATENTS Number Country Date 482,111 Great Britain Mar. 23, 1938 c ee mg, 

